Air- and nitrogen-packed samples from the same production lot of peanut butter, stored in the dark at 25°C for 1 yr, were analyzed periodically by direct gas chromatography. The ratio of methylbutanal to hexanal was consistently higher in nitrogen-packed than in equivalent air-packed samples and decreased throughout the storage period for both types of samples. Correlation coefficients, significant at 0.1%, were 0.99 for nitrogen-packed and 0.96 for air-packed samples. A total of 35 volatile components of peanut butter were identified by combined direct gas chromatography—mass spectrometry, and another 6 were tentatively identified.